The present invention relates to a printing apparatus for transferring a color agent to a sheet, thereby forming an image thereon.
Among conventional printing apparatuses of this type, there are thermal transfer printing machines which print by heating a ribbon impregnated with a color agent. Generally small-sized, low-priced, noise-free, and capable of printing on ordinary paper, these printing machines have recently been used for computers, recorders for the output of word processors, and copying apparatuses.
In printing, in the prior art printing apparatuses of this type, an unused ribbon wound on one roll shaft is wound up as a used ribbon by the other roll shaft after it is used as a printing medium.
Therefore, a conventional transfer material unit is provided with only a roll shaft and a ribbon (transfer material) wound thereon. In setting a replaceable ribbon in the printing apparatus, for example, an operator must mount the roll shaft wound with the ribbon on a ribbon mounting shaft attached to the apparatus housing, draw out one end portion of the ribbon from the roll shaft, and then pass the one end portion around a separate vacant roll shaft by hand.
Thus, the prior art printing apparatuses require much time and labor for setting the ribbon.